Fixed dorsal electrode system for electrocardiography



Nov. 4, 1969 J. VI 3,476,104

FIXED DORSAL ELECTRODE SYSTEM FOR ELECTROCARDIOGRAPHY Filed Aug. 8, 1967 FIG. I.

INVENTOR James B. Davis BY [j zowA (YB Q2,

ATTORNEY United States Patent 3,476,104 FIXED DORSAL ELECTRODE SYSTEM FOR ELECTROCARDIOGRAPHY James B. Davis, 69 Ridgedale Drive,

Jackson, Tenn. 38301 Filed Aug. 8, 1967, Ser. No. 659,188 Int. Cl. A61b 5/04; A61n 1/04 U.S. Cl. 1282.06 7 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION The invention relates to the field of electrode-cardiography wherein readings are taken with conventional recording mechanism to enable a skilled cardiologist to determine the condition of a patients heart. It has been the common practice to engage separate electrodes at differ ent points relative to the front of the torso of a patient reclining on his back on a table or bed. These electrodes are wholly separate from each other and are placed in position by a technician who coats the selected spots on the body and/ or the electrodes to make suitable contact with the body. A suitable liquid or gelatinous material is used to assure the proper electrical contact. Other methods employed for this purpose involve the use of the electrodes fixed to the extremities of the human body, for example, by strapping electrodes around the wrists.

SUMMARY OF THE INVENTION The invention comprises two separate rectangular casings having a pair of electrodes carried by each casing and adapted for electrical connection with a conventional recording mechanism. These casings are placed on a table, and a patient with his back uncovered lies upon the casing to make efiicient electrical contact with the electrodes, the weight of the patients body assuring such electrical contact. In order that the two casings may be made in the form of a unit, a slide projects into each casing so that the distance between the electrodes of the two casings may be varied according to the height of the patient. When the apparatus is not in use, the slide permits the two casings to be moved into abutting relation to minimize space. Each casing carries in an edge thereof a pair of jacks electrically connected with the respective electrodes, and plugs from a conventional recording mechanism are plugged into the jacks to convey the electrical impulses to the recording mechanism.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a fragmentary perspective view showing a table or the like with the device of the present invention in position on the table and connected to a recording mechanism, a patient being shown on the table in broken lines;

FIGURE 2 is a plan view of the device, parts being broken away; and

FIGURE 3 is an edge elevation of the device.

Referring to the drawings, the numeral 10 designates a table or other support upon which a patient 11 lies prone on his or her back with the back uncovered to make proper electrical contact with the elements to be described.

The present device compn'ses a pair of casing sections 12 of hollow construction, each provided with electrodes 14 preferably set in insulation 15 carried by the casing sections.

Each casing has an inner casing 16 having side walls 17 parallel to each other and remote end walls 18. Each side wall 17 turns inwardly as at 19 and its extremity extending into the casing 17. The extremities 20 serve as guides for a slide 22 which serves to permanently connect the two casing sections to each other for convenience in handling. At opposite extremities, the slide 22 is provided with outstanding lugs 23 engageable with the extremities 20 to limit movement of the casings 12 away from each other. When the apparatus is not in use, the casings 12 may be pushed together so that their adjacent edges 25 will move into abutting relation-ship.

To facilitate the use of the apparatus as described below, one of the casing sections is provided with an arrow 28.

One electrode of each casing is provided with a wire 30 leading to a jack 31 carried by the adjacent end wall of the casing. The back wall 18 of each casing 17 is spaced from the back wall 32 of each casing 12 to provide a space for the passage of a conductive wire 33 to a second jack 34. Thus, the two electrodes of each casing 12 are connected to jacks, and wires 35, leading to a conventional recording mechanism 36 may be plugged into the jacks 31 and 34.

OPERATION The device is placed on a suitable examining table or bed as shown in FIGURE 1, and the wires 35 are plugged into the jacks 31 and 34. The electrodes are then preferably swabbed with a solution of sodium chloride or isopropyl alcohol, or the electrodes are covered with small gauze pads soaked in such solution.

With the subject sitting straight up and stripped to the waist, the technician then visually centers the sighting arrow '28 with respect to the subjects spine. This centering technique insures that the heart area is encompassed by the perimeter of the four electrodes. The device is then expanded by pulling the upper casing 12, that is the casing toward the upper part of the patients body, so that the upper dorsal electrodes 14 will lie approximately at the level of the second or third ribs and the lower dorsal electrodes will be arranged approximately at the iliac crest. This serves to insure the monitoring of all impulses and to allow for unknown conditions such as cardiomegaly. After these adjustments have been made, requiring only a very few seconds, the patient is then instructed to lie straight back onto the device.

The technician then checks to make sure contact has been made with all four electrodes. In subjects with a high spinal arc, it may be necessary to build up the height level of the lower casing 12, that is, the casing toward the lower part of the patients torso. This may be done with one or more towels to insure good electrical contact. The technician may then proceed to prepare the electrocardiogram in the conventional manner, and when the test is completed, the patient merely has to get up to disconnect the apparatus.

If several electrocardiograms are to be done in succession, the device may be left connected in the described manner. In cases involving female subjects, it might be advisable to procure a regular hospital gown and cut a large rectangular opening at the back thereof, thereby allowing the use of the device on female patients without subjecting them to full exposure.

The use of the present device in the manner described serves many purposes other than the principal purpose of providing electrical contact. The body of the patient becomes a very effective shield against outside electrical influence and the weight of the subjects body serves to guarantee good electrical contact as well as minimizing the incidence of somatic tremor. Also, drifting (a deviation in the base line of the electrocardiogram of a horizontal trace) is minimized by the use of the invention inasmuch as the possibility of unsatisfactory electrode contact is substantially eliminated. Moreover, the construction eliminates the need of a securing device or devices for the electrodes since the weight of the patients body serves to keep the electrodes properly positioned and in efficient electrical contact with the body. The device also reduces the incidence of psychological trauma frequently associated with electrocardiography by eliminating the straps, wires, etc., associated with conventional systems.

Of course the device is capable of application in any position of the body, and while preferably used in the manner described, may even be used vertically with a suitable mount or strap system. It also will be apparent that the device is usable in situations where conventional systems would not be applicable, namely, in cases in which the extremities are severely burned or otherwise injured or enclosed in casts. The use of the device greatly reduces the total time required to prepare electrocardiograms, and the device is adaptable to all electrocardiograph systems. No change is required in standard marking, mounting and interpreting procedures, and the device is usable in all situations requiring continuous monitoring of the electrocardiographic impulses.

The device allows percordial leads to be produced in a conventional manner, and the device may be portable or in a permanently mounted position. Moreover, the device may be used on the chest, if necessary, for example in cases such as spinal surgery.

From the foregoing it will now be seen that there is herein provided an improved electrode system which accomplishes all of the objects of this invention and others, including many advantages of great practical utility and commercial importance.

As various embodiments may be made of this inventive concept, and as many modifications may be made in the embodiments hereinbefore shown and described, it is to be understood that all matter herein is to be interpreted merely as illustrative and not in a limiting sense.

I claim:

1. In a fixed dorsal electrode system for electrocardiography:

a relatively fiat casing structure adapted to be placed on a support on which a patient reclines,

a plurality of electrodes carried by the top of said casing structure for engagement with the skin of the patient and in electrical contact therewith,

an electrocardiographic recording mechanism, and

wires connecting said electrodes to said recording mechanism.

2. A system according to claim .1 wherein said casing structure is formed of a pair of similar casing sections adapted to be spaced from each other in a direction of the height of the patient to engage proper portions of the patients body.

3. A system according to claim 1 wherein said casing structure is formed of a pair of similar casing sections adapted to be spaced from each other in a direction of the height of the patient to engage proper portions of the patients body, and

means connecting said casing sections in slidable engagement to provide for adjustment of said casing sections toward and away from each other.

4. A system according to claim 1 wherein said casing structure is formed of a pair of similar casing sections adapted to be spaced from each other in a direction of the height of the patient to engage proper portions of the patients body, said casing sections being hollow, and

a slide entering said casing sections through adjacent edge portions thereof to provide for movement of said casing sections toward and away from each other.

5. A system according to claim 1 wherein said casing structure is formed of a pair of similar casing sections adapted to be spaced from each other in a direction of the height of the patient to engage proper portions of the patients body, said casing sections being hollow, edge portions of said casing sections being provided with openings, and

a slide having end portions entering respectively said openings in said casing sections and having means for limiting movement of said casing sections from each other.

6. A system according to claim 1 wherein said casing structure is formed of a pair of similar casing sections adapted to be spaced from each other in a direction of the height of the patient to engage proper portions of the patients body,

the top of each casing section having a pair of said electrodes spaced from each other laterally of the patients body, the top of the casing section engageable with the lower portion of the patients body being provided centrally of the electrodes of said section with an indicator to facilitate the centerin of the device laterally of the patients body.

7. A system according to claim 1 wherein said casing structure is formed of a pair of similar casing sections adapted to be spaced from each other in a direction of the height of the patient to engage proper portions of the patients body,

a slide entering said casing sections through adjacent edge portions thereof to provide for movement of said casing sectionstoward and away from each other,

electrical jacks carried by corresponding edge walls of said casing sections to receive plugs carried by wires leading to said recording mechanism, and

a wire extending from each of said electrodes to one of said jacks within the respective casing sections.

References Cited UNITED STATES PATENTS 720,020 2/1903 Grimshaw 128-405 796,533 8/1905 Rayner 128-416 X 3,025,857 3/1962 Browner 128-376 3,323,514 6/1967 Barrett 128-206 3,387,608 6/1968 Figar 128-2.06

WILLIAM E. KAMM, Primary Examiner US. Cl. X.R. 

